Preheat oven to 350℉. Line two baking sheets with parchment paper and set aside.
In a medium bowl, whisk or sift together the flour, whole wheat flour, baking soda and salt. Set aside.
In the bowl of an electric mixer, beat together the butter, peanut butter, and honey until light and fluffy, about 1 minute. Add in the brown and granulated sugars and beat on high until light and fluffy, about 3 minutes. Stir in the egg and vanilla extract. Scrape down the sides and bottom of the bowl to evenly incorporate. Add in the dry ingredients and stir until just combined. Do not over-mix.
Scoop out the dough into even balls (using a small ice cream scoop) and roll gently between the palms of your hands to smooth out. You’ll need to do this with damp hands. Place on prepared baking sheets and freeze for about 10 minutes to firm up a bit. Using damp hands, gently press down on the cookies. Dip a fork into warm water and create a criss cross pattern on top of the cookies.
Bake for about 16 minutes, rotating pans halfway through baking, or until lightly golden brown around the edges. Remove from oven and allow to cool down on baking sheets for about 5 minutes. Transfer to a wire rack to cool completely.
To make chocolate ganache, heat the heavy cream in a small saucepan until just scalded. Pour into a bowl, over the chocolate chips. Allow to sit, untouched, for about 5 minutes. Whisk until glossy and smooth.
Scoop the banana ice cream onto half of the cookies and then sandwich with the remaining cookies. Place on baking sheet and freeze for about 30 minutes. Dip the sandwiches, halfway, into the dark chocolate ganache and roll around in the chopped nuts. Return to freezer for another 30 minutes before eating. Wrap any leftover sandwiches individually in plastic wrap and keep in freezer for up to 5 days. Enjoy!